本文章最後由 iheby 於 2016-9-15 17:26 編輯
粒子理論:- 二次重力 - 從弱到強 @香港科技大學 賽馬會高等研究院
Seminar:- Quadratic Gravity: From Weak to Strong
More than three decades ago, quadratic gravity was found to present a perturbative, renormalizable and asymptotically free theory of quantum gravity. Unfortunately the theory appeared to have problems with a spin-2 ghost. In this talk, the speaker will revisit quadratic gravity in a different light by considering the case that the asymptotically free interaction flows to a strongly interacting regime. This occurs when the coefficient of the Einstein-Hilbert term is smaller than the scale that the quadratic couplings grow strong. Here QCD provides some useful insights. By pushing the analogy with QCD, she conjectures that the non-perturbative effects can remove the naive spin-2 ghost and lead to the emergence of general relativity in the IR, with the Planck mass identified as the strong gravity scale. This theory has new static spherically symmetric.
時間：2016.09.13(二) 14:00
地點：香港科技大學 李兆基校園 盧家驄薈萃樓 賽馬會高等研究院 4042室
講者：Dr Jing Ren (University of Toronto)
語言：英語
免費講座，觀迎公眾參加，座位先到先得
【講者】
Kerr-de Sitter黑洞的穩定性 @香港科技大學 賽馬會高等研究院
Lecture:- The Stability of Kerr-de Sitter Black Holes
In this lecture, the speaker will discuss Kerr-de Sitter black holes, which are rotating black holes in a universe with a positive cosmological constant, i.e. they are explicit solutions (in 3+1 dimensions) of Einstein's equations of general relativity. They are parameterized by their mass and angular momentum.
He will discuss the geometry of these black holes as well as that of the underlying de Sitter space, and then talk about the stability question for these black holes in the initial value formulation. Namely, appropriately interpreted, Einstein's equations can be thought of as quasilinear wave equations, and then the question is if perturbations of the initial data produce solutions which are close to, and indeed asymptotic to, a Kerr-de Sitter black hole, typically with a different mass and angular momentum. In this lecture, based on joint work with Peter Hintz, the speaker will discuss geometric aspects of the stability problem, in particular showing that Kerr-de Sitter black holes with small angular momentum are stable in this sense.
時間：2016.09.12(二) 15:30 ~ 17:00
地點：香港科技大學 李兆基校園 盧家驄薈萃樓 高研院演講廳
講者：Prof András Vasy (Professor of Mathematics, Stanford University)
語言：英語
免費講座，觀迎公眾參加，座位先到先得
【講者】
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